Printing – Stenciling – Multicolor
Reexamination Certificate
2001-05-07
2003-11-04
Yan, Ren (Department: 2854)
Printing
Stenciling
Multicolor
C101S116000, C101S128400, C101S129000
Reexamination Certificate
active
06640702
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to stencil printing machines and more particularly to a stencil printing machine equipped with plural printing drums for achieving a multi-color printing and a method of controlling the same.
2. Description of the Related Art
Various research and development work have been undertaken to provide a stencil printing machine of the type which enables a multi-color printing with the use of a plurality of printing drums, a first typical example of which is disclosed in
FIG. 6
which shows a part of a structure of the prior art stencil printing machine. In
FIG. 6
, first and second printing drums
101
and
102
and a press drum
103
are rotatably supported in a frame body (not shown) such that the first and second printing drums
101
and
102
are located in close proximity to an outer periphery of the press drum
103
and are angled at 90 degrees relative to a central axis of the press drum
103
. Outer circumferential peripheries of the respective first and second printing drums
101
and
102
carry thereon stencil clamping bases
101
a
and
102
a
, respectively, which support thereon sheet clamping segments
101
b
and
102
b
for clamping stencil sheets (not shown) onto the stencil clamping bases
101
a
and
102
a
, respectively.
Further, screens
105
are wound on the outer circumferential peripheries of the first and second printing drums
101
and
102
in a stretched state with the use of the stencil clamping bases
101
a
and
102
a
and springs
104
and
105
, with each of the screens
105
being formed of a porous or mesh structure which allows printing ink to permeate. Inner press rollers
106
and
107
are located inside the screens
105
of the first and second printing drums
101
and
102
, respectively, with the inner press rollers
106
and
107
being moveable between a wait position not to press the screens
105
and a press engagement position to press the screens
105
.
During printing operation, the inner press rollers
106
and
107
are maintained in the press position, in which the screens
105
are expanded outward. Also, it is arranged such that the screen
105
of the first printing drum
101
is supplied with printing ink in a first color by the inner press roller
106
and the screen
105
of the second printing drum
102
is supplied with printing ink in a second color by the inner press roller
107
. The outer circumferential periphery of the press drum
103
is provided with a print sheet clamp segment
109
, for clamping a leading edge of a print sheet
108
, which clamps the leading edge of the print sheet
108
transferred from a paper feed section
110
and release the leading edge of the print sheet
108
at a position in the vicinity of an inlet portion of a sheet discharge section
111
.
Now, the stencil printing machine thus arranged operates as follows. A leading edge of a first stencil sheet, which has been made on the basis of image data in a first color of an original is clamped with the sheet clamp segment
101
b
of the first printing drum
101
, and a leading edge of a second stencil sheet, which has been made on the basis of image data in a second color of the original, is clamped with the sheet clamp segment
102
b
of the second printing drum
102
, with the stencil sheets being mounted onto the outer circumferential peripheries of the respective screens
105
.
Next, the first and second printing drums
101
and
102
and the press drum
103
are rotated in synchronism with one another in directions as shown by arrows in
FIG. 6
, thereby causing the print sheet
108
to be transferred between the first printing drum
101
and the press drum
103
from the paper feed section
110
. The print sheet
108
thus transferred is clamped with the print sheet clamp segment
109
of the press drum
103
, allowing the print sheet to pass along the outer circumferential periphery of the press drum
103
between the first printing drum
101
and the press drum
103
. During this passing step of the print sheet, the inner press roller
106
is brought into press engagement with the screen
105
of the first printing drum
101
which is consequently expanded outward, allowing printing ink to be transferred to the print sheet
108
to reproduce a desired image pattern with a first color via a perforated image area of the first stencil sheet.
The print sheet
108
, which has passed between the first printing drum
101
and the press drum
103
, then passes between the second printing drum
102
and the press drum
103
. During this passing step of the print sheet, the inner press roller
107
is brought into press engagement with the second screen
105
which is consequently expanded outward, allowing printing ink to be transferred to the print sheet
108
to reproduce a desired image pattern with a second color via a perforated image area of the second stencil sheet. As the sheet clamp segment
109
of the press drum
103
is rotated to a position near the inlet of the sheet discharge section
111
, the sheet clamp segment
109
is released, with the released print sheet
108
being discharged to the given discharge position by the sheet discharge section
111
. In this manner, two-color printing is completed.
A second prior art stencil printing machine is shown in
FIG. 7
, which is a schematic view of a part of the structure of the stencil printing machine. In
FIG. 7
, first and second printing drums
101
and
102
are rotatably supported in a frame body (not shown), and outer circumferential peripheries of the first and second printing drums
101
and
102
carry thereon stencil clamping bases
101
a
and
102
a
, respectively, which support thereon sheet clamping segments
101
b
and
102
b
for clamping stencil sheets (not shown) onto the stencil clamping bases
101
a
and
102
a
, respectively.
Further, the outer circumferential peripheries, except the first and second sheet clamping bases
101
a
and
102
a
, of the first and second printing drums
101
and
102
are constructed by respective porous structures that allow printing ink to permeate. Inside the first and second printing drums
101
and
102
, respective printing ink supply means are located to supply printing ink, in first and second colors, to the outer circumferential peripheries of the first and second printing drums, respectively.
Also, press rollers
120
and
121
are rotatably supported in close proximity to the first and second printing drums
101
and
102
, respectively.
The press rollers
120
and
121
are moveable between a wait position (shown by a solid line in
FIG. 7
) in which the press rollers
120
and
121
are held out of press engagement with the outer circumferential peripheries of the first and second printing drums
101
and
102
, respectively, and a press engagement position (shown by a phantom line in
FIG. 7
) in which the press rollers
120
and
121
are brought into press engagement with the outer circumferential peripheries of the first and second printing drums, respectively. During printing operation, the inner press rollers
120
and
121
are maintained in the press engagement position. A paper feed section
122
is arranged to supply a print sheet
108
between the first printing drum
101
and the press roller
120
, and a sheet discharge section
123
receives the print sheet
108
discharged between the second printing drum
102
and the press roller
121
, thereby discharging it to a given position.
Now, the stencil printing machine thus arranged operates as follows. The leading edge of the stencil sheet made on the basis of image data in a first color and the leading edge of the stencil sheet made on the basis of image data in a second color are clamped with the sheet clamp segment
101
b
of the first printing drum
101
and the sheet clamp segment
102
b
of the second printing drum
102
, respectively, causing the stencil sheets to be mounted onto the outer circumferential peripheries of the respective printing drums. Next, the first an
Hara Yoshikazu
Watanabe Hiroshi
Berkowitz Marvin C.
Nath Gary M.
Novick Harold L.
Riso Kagaku Corporation
Yan Ren
LandOfFree
Stencil printing machine and method of controlling the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stencil printing machine and method of controlling the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stencil printing machine and method of controlling the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3116522